I've got a program that records data to an SD file every time an interrupt is received and the event handler calls its function. The called function consists of a few Serial.print and data.print commands, and when there isn't a card inserted, things work fine. However, when I insert the card, the program just halts.

I'm using the sparkfun.com microDC shield with the SdFat.h library under Arduino 0023.

I'm using the sparkfun.com microDC shield with the SdFat.h library under Arduino 0023.

Thanks for including this detail.

I have noticed in the past that this shield seems to reset the Arduino when an SD card is inserted--I'm not sure why.

You could try contacting SparkFun tech support via email.

--Philip;

P.S. My *assumption* is that something is being shorted when the card is being inserted--perhaps related to a "card present" pin--in which case I'd be tempted to look for a trace to cut if SF tech support can't help.

I solved the problem. The issue was that I'm stacking Arduinos in an I2C arrangement, and the SD shield was connected through to both master and slave Arduinos. Once I cut the connections and passed control of the SD shield to the master only, the problem vanished.